I'm making a 5' wide by 3' high cutout in my wall between my kitchen and family room. I"m pretty handy, but I'm not quite sure how to handle this project with the least amount of work. I'm sure the wall is not load supporting. I'm pretty sure there are no pipes or wire in the wall where I'll be cutting. Here is how I was going to go about it: Make outline of cutout on the wall on one side. Using a pallet knife score the line until I get through the sheetrock. Demo the sheetrock within the cutout and remove it. Check for wires and or pipes. Use my saws-all and cut through 2x4s and other side of sheetrock. Attach new 2x4s top and bottom. Cut back sides till I hit existing 2x4s. Apply strip of sheetrock to top and bottom, both side to cover new 2x4s. Cover inner faces of top and sides with sheetrock. Apply corner bead to top and side 2x4s. Attach wooden board on the bottom 2x4 with small overhand on both sides. Spackle, sand, and paint. Sounds good? Also is there a standard height for this type of hole? What is the height if I decide I want to use stools and mount a narrow counter on top at some point?

Hello Chris:
Your framing plan is correct. The bar stool height for the counter is 36" to 42". Of course, the 36" matches the other countertops in the kitchen. It sounds like you have this one whipped.
Glenn